The parameters for creating the elevation, see WellKnownEditKeys.Elevation and parameters to configure the creation dialog with WellKnownParameterKeys.Elevation.Creation.
Stream content
Additional data that is used to create a new Elevation from, e.g. a 2D or 3D XML file.
Returns
Returns an IOperationInfo to determine if the Elevation can be created with the given parameters. If it's not possible to create the Elevation a list of restrictions is attached to it.